Extraosseous talotarsal stabilization devices: a new classification system

An evaluation of subtalar titanium screw arthroereisis for the treatment of symptomatic paediatric flatfeet - early results

BACKGROUND

Idiopathic flexible flatfoot is a common condition in children which typically improves with age and remains asymptomatic. However, the condition can sometimes be more severe, and cause mechanical impairment or pain. The aim of the study was to perform a prospective clinical, radiological, podoscopic and pedobarographic assessment (static and dynamic) of subtalar titanium screw arthroereisis for the treatment of symptomatic, idiopathic, flexible flatfeet.

METHODS

A prospective, consecutive, non-controlled, cohort, clinical follow-up study was performed. In total, 30 patients (41 feet), mean age 10 (6 to 16 years), were evaluated. Clinical and standing radiological assessments, static and dynamic pedobarography, as well as podoscopy, were performed before surgery and at final follow-up.

RESULTS

Treatment was associated with significant improvements in heel valgus angle, radiographic parameters (lateral and dorso-planar talo-first metatarsal angle, calcaneal inclination angle, talar declination angle, longitudinal arch angle) and podoscopic parameters (Clark's angle, Staheli's arch index and Chippaux-Smirak index). Significant increases were noted for lateral loading, forefoot contact phase and double support / swing phase, and reduced medial loading (dynamic pedobarography), as well as lateral midfoot area and loading, but decreased were observed for medial forefoot loading (static pedobarography). Four patients reported persistent pain in the sinus tarsi region (six feet), and in one case, the implant was replaced for a larger one due to undercorrection. No overcorrections or infection complications were noted in the study group.

CONCLUSIONS

Subtalar arthroereisis is a minimally-invasive and effective surgical method for treating symptomatic, idiopathic, flexible flatfeet; it has an acceptable complication rate with good early clinical results.

LEVEL OF EVIDENCE

II b.

Mid-term assessment of subtalar arthroereisis with Talar-Fit implant in pediatric patients with flexible flatfoot and comparing the difference between different sizes and exploring the position of the inserted implant

Background

Subtalar arthroereisis (STA) has gained growing acceptance as a viable approach solution for the management of pediatric flexible flatfoot. However, STA still remains controversial. The purpose of this study is to assess the effect of STA using the Talar-Fit implant for treating pediatric flexible flatfoot. Specifically, the aims of the study are as follows: first, to present the mid-term outcomes of STA using the Talar-Fit implant; second, to compare the radiographic and clinical outcomes associated with varying sizes of Talar-Fit implant; and third, to analyze the optimal position of the inserted implants.

Methods

A retrospective analysis was conducted on a cohort of 57 pediatric patients diagnosed with flexible flatfoot (77 feet) who underwent STA utilizing Talar-Fit between January 2014 and December 2021. The participants were categorized into five groups according to the size of the implant: Group 8, Group 9, Group 10, Group 11, and Group 12. The evaluation included the assessment of clinical function using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hind foot score, as well as the assessment of radiographic data such as the calcaneal pitch angle (CPA), lateral Meary angle (LMA), talar declination angle (TDA), and medial longitudinal arch angle (MLAA) were evaluated. Furthermore, the position of the inserted implants was also recorded, including angle, depth, and distance. The comparison of pre- and postoperation was conducted using the paired Student's t-test, whereas the analysis of differences among subgroups was performed using the Wilcoxon rank-sum test. A P-value < 0.05 is considered statistically significant.

Results

In total, 57 pediatric patients (77 feet) were successfully followed-up for an average period of 26.8 months. The overall AOFAS score significantly improved from 58.6 ± 10.9 to 85.2 ± 8.6 (P < 0.001). Furthermore, the LMA decreased from 20.3° ± 3.6° to 4.5° ± 1.3°, the CPA increased from 14.8° ± 1.6° to 23.6° ± 2.7°(P < 0.05), the TDA decreased from 40.2° ± 2.3° to 25.5° ± 3.2°(P < 0.05), and the MLAA decreased from 140.1° ± 2.8° to 121.4° ± 3.9°(P < 0.05). No statistically significant differences were observed among subgroups regarding the final outcomes. The improvements of CPA, TDA, and MLAA among different groups were significantly different; however, the adjusted P-values were all greater than 0.05. The implant were inserted at a mean angle of 89.5° ± 2.4°, a mean depth of 0.9 mm ± 2.1 mm, and a mean distance of 9.9 mm ± 0.9 mm. Eight patients experienced complications, including six cases of pain occurrence and two cases of implant dislocation.

Conclusion

STA with Talar-Fit has demonstrated satisfactory mid-term outcomes. A Talar-Fit with a larger size may demonstrate a superior effect when compared with that of a smaller size. The implants were inserted in a similar position, indicating that the medial edge of the implant may be possible to transcend the midline of the talus neck.

Clinical Outcomes Following Treatment of Recurrent Talotarsal Joint Dislocation Using a Type II Extraosseous Talotarsal Stabilization Implant-A Long-Term Follow-Up Study

Collapsing foot deformity (CFD) and its resulting sequelae caused by recurring talotarsal joint dislocation (RTTJD) affects pediatric and adult patients. An extraosseous talotarsal stabilization (EOTTS) procedure, a subset of subtalar arthroereisis (SA) procedures, is recommended as a minimally invasive, first in-line surgical treatment option for CFD. The aim of this multicenter, retrospective study was to evaluate patient-reported outcomes measures in patients who were treated for RTTJD with Type II EOTTS implants. Sixty-seven cases having a median age of 38 years (range: 10-74) with more than 5 years of follow-up were included in this study. The mean postoperative visual analog scale and Maryland Foot Score was 1.0 ± 1.9 and 92.3 ± 11.3, respectively, indicating excellent clinical outcomes. Subjectively, 88% cases reported as being satisfied with the outcome, 94% cases said they would recommend EOTTS, and 93% said that, if necessary, they would repeat it on their contralateral foot. A subgroup analysis revealed that while not statistically significant, clinical outcomes were slightly better in pediatric patients compared to adults. Implant removal rate was 4.5% (3 cases), and these were in the adult group only. Rate of minor issues such as pain, stiffness, discomfort, etc. was 15%; however, no serious adverse effects or complications were observed in any patient. This study suggests that EOTTS is an effective surgical treatment option wherein successful long-term clinical outcomes with low failure rates can be achieved in a select patient population.

Prospective, Long-Term Functional Outcomes of Extra-Osseous Talotarsal Stabilization (EOTTS) Using HyProCure in Adult Patients with Talotarsal Joint Instability: Assessment of Physical Activity and Patient Satisfaction

BACKGROUND

The partial dislocation of the talus from the calcaneus and navicular bones is a primary factor leading to a prolonged overpronation during weightbearing. This study aimed to assess the possibility of returning to physical activity and long-term patient satisfaction after an extra-osseous talotarsal stabilization (EOTTS) procedure with a HyProCure sinus tarsi implant for partial talotarsal joint dislocation (TTJ).

METHODS

A total of 41 adult patients (61 feet), with an average age of 46.41, were included and treated surgically with EOTTS as a stand-alone surgery. Physical activity and functional scores were assessed pre- and post-operatively using questionnaires-the UCLA Activity Score, Symptom-Related Ankle Activity Scale (SAAS), Sports Frequency Score (SFS), Lower Extremity Functional Scale (LEFS), and VAS scale. Satisfaction was assessed on a ten-point scale. The follow-up period was on average 8.61 years (from 7.33 to 10.31).

RESULTS

EOTTS had a positive impact on physical activity, and a high rate of patient satisfaction (8.95 ± 1.9) was noted. The treatment led to a reduction in foot pain, as well as an increase in SAAS and LEFS scores (15,6% and 19,3%, respectively, p <0.01). The VAS pain score decreased by 18,6% (p <0.001). SFS and UCLA scores showed a small increase, but it was not statistically significant. A positive correlation was noted between patient satisfaction and time of physical activity per week (R = 0.33, p =0.04), and also between patient satisfaction and SAAS scores (R = 0.43, p =0.005). Pain from other joints (knee, hip) was eliminated or reduced in 40% of patients after surgery.

CONCLUSIONS

EOTTS with a HyProCure implant is an effective long-term treatment option for partial talotarsal joint dislocation, leading to a reduction in foot pain and increased patient satisfaction, and allowing for a return to physical activity.

Patient Outcomes Following Extra-Osseous Talo-Tarsal Stabilization for Foot Hyperpronation

The aim is to present a single-center case series of patients with symptomatic hyperpronated feet treated with arthroereisis by using a second generation extra-osseous talo-tarsal stabilization device. This case series enrolled 123 feet in 87 patients (20 [6-75] years) treated with arthroereisis, either isolated (76 cases) or combined procedure (47 cases). At their final follow-up, a patient reported questionnaire (overall satisfaction, foot stability and shape, activities of daily living, pain level, and analgesics usage) was distributed. The average postoperative follow-up period was 30 (13-55) months. Nineteen (15%) cases required at least one revision surgery: the implant was manipulated in 5 (4%), while 14 cases (11%) required definitive implant removal. The predominant reason for implant removal was pain (50%), followed by implant migration (27%). The pediatric population with isolated procedure showed lowest revision rate (5%), while adults with combined ankle/hindfoot procedures demonstrated revision rate of 50%. The overall patient satisfaction after arthroereisis was 84%. The patients' perceived improvement in foot stability was 75%, foot shape 85%, and activities of daily living 64%. Eighty-two percent of cases reported no analgesics usage in the last month and mean visual analogue scale (0-10) pain level decreased from 5.5 to 2.2 (p < .001). The subgroup analyses of patient-reported questionnaires revealed the best outcome in the pediatric-isolated cases, while adults with combined procedures reported the lowermost outcome. Extra-osseous talo-tarsal stabilization demonstrated a low rate of revisions surgery and a high satisfaction rate as an isolated procedure. Patients with conjoined procedures experienced more revisions and considerably lower satisfaction rates.

Arthroereisis: Treatment of Pes Planus

Arthroereisis is a surgical procedure primarily used to treat flexible pes planus (flatfoot) in pediatric and young adult patients. The principal goal of subtalar arthroereisis is to relieve pain and restore function. This is primarily done by restoring the medial foot arch without fusing the subtalar joint and without requiring a long recovery period needed after osteotomies. Although the procedure can be performed in isolation to treat flexible flatfoot, it can also be performed as an ancillary in the treatment of tarsal coalition, posterior tibial tendon dysfunction, and accessory navicular syndrome. Various implants and multiple surgical techniques exist for arthroereisis, such as the sinus tarsi implant and calcaneo-stop. The type of device and the surgical approach to proceed with are based on the surgeon’s discretion rather than an evidence-based protocol. Multiple complications can arise from subtalar arthroereisis, most commonly sinus tarsi pain. Currently, there is a dearth of quality clinical data and evidence on the long-term outcomes and complications of arthroereisis. This lack of literature for a commonly performed procedure validates the need for future studies to better guide a standard protocol, reach consensus on well-defined indications and contraindications, provide expected complications, and improve the practice of evidence-based medicine.

HyProCure for Pediatric Flexible Flatfoot: What Affects the Outcome

BACKGROUND

The high success rate, minimal invasion, and safety of subtalar arthroereisis (SA) have made it a primary mode of surgical management for pediatric flexible flatfoot. The HyProCure procedure is a new surgery for SA, However, very few available studies reported the therapeutic effects of the HyProCure procedure, especially in pediatric flexible flatfoot. The main aim of the present study was to investigate the clinical and radiological outcomes of the HyProCure procedure for pediatric flexible flatfoot and analyze the risk factors for therapeutic outcomes and sinus tarsi pain.

METHODS

In this retrospective cohort study, 69 pediatric flexible flatfoot patients (107 feet) who underwent the HyProCure procedure were included between July 2015 and September 2020. All patients underwent the HyProCure procedure with or without gastrocnemius recession. The Maryland foot score (MFS), visual analog scale (VAS), radiographic data, and complications were assessed at a minimum 1-year follow-up and statistically analyzed.

RESULTS

The mean follow-up was 35.9 months (range, 13-73 months). At the last follow-up, VAS (0.64 ± 1.16) was significantly lower than the preoperative VAS (4.06 ± 1.43) (p < 0.001); MFS (90.39 ± 12.10) was significantly higher than the preoperative MFS (71.36 ± 10.25) (p < 0.001). The AP talar-second metatarsal angle (T2MT angle) significantly decreased from 17.0 ± 5.4° preoperatively to 11.4 ± 5.2° at the last follow-up (p < 0.001). The lateral talar-first metatarsal angle (Meary's angle) significantly decreased from 13.8 ± 6.4° preoperatively to 6.3 ± 5.0° at the last follow-up (p < 0.001). The calcaneal declination angle (Pitch angle) significantly increased from 13.5 ± 4.9° preoperatively to 14.8 ± 4.4° at the last follow-up (p < 0.001). Logistic regression analysis indicated that patients with a longer distance from the tail end of the implant exceeding the longitudinal talar bisection line had 275.8% greater odds of MFS < 90. Yet, no risk factors were found in connection with sinus tarsi pain.

CONCLUSIONS

The HyProCure procedure for pediatric flexible flatfoot achieved satisfactory curative effects with a low complication rate; implant depth was associated with unsatisfactory postoperative outcome.

Short Term Clinico-Radiological Outcome of Extra Osseous Talo-Tarsal Stabilization (EOTTS) in Flat Foot: An Indian Perspective

INTRODUCTION

Flexible flat foot is one of the most common foot conditions found amongst any age group across the world. One very important reason for this condition is the incongruency or partial dislocation of one or more joints within the talo-tarsal mechanism. This flexible talo-tarsal malalignment is termed as recurrent talo-tarsal joint dislocation (RTTJD).

MATERIALS AND METHODS

Between 2016 and 2018, 32 patients were advised Extra osseous talo-tarsal stabilization (EOTTS) as a standalone procedure for RTTJD following detailed clinical examination including foot posture index (FPI) scoring and weight-bearing radiographic evaluation. Subjective assessment was done through Maryland Foot Score (MFS) questionnaire. Radiological parameters like talar declination angle, talar second metatarsal angle and tibio-calcaneal valgus angle were assessed for preoperative and postoperative comparison. 15 patients (20 feet) underwent surgery and rest 17 patients (25 feet) became our control group. A retrospective record analysis of longitudinal data was done over a period of 4 years. The purpose of this study is to depict the short-term results of EOTTS procedure in terms of functional and radiological improvement and compare it with the non-surgical group.

RESULT

Significant improvement was seen in MFS from 67.31 ± 16.04 to 95.47 ± 4.36 over a mean follow-up period of 30.66 ± 7.09 months. Total FPI improved by 96.83 ± 4.80% at final follow-up of EOTTS group. Radiologically, maximum correction achieved was in coronal plane (93.07 ± 30.05%).

CONCLUSION

EOTTS, as a standalone procedure improved the foot radiological angles and restored the normal foot biomechanics significantly in presence of competent spring ligament and posterior tibial tendon. This procedure resulted in excellent patient satisfaction score as assessed by MFS questionnaire.

LEVEL OF EVIDENCE

III.

Biomechanical assessment of two types and two different locations of subtalar arthroereisis implants for flexible flatfoot: A cadaveric study

BACKGROUND

Subtalar arthroereisis refers to the implantation of a sinus tarsi implant for the treatment of flexible flatfoot. The purpose of this study was to compare the ability to correct the flatfoot deformity and contact pressure of the posterior subtalar joint between two types of self-locking wedge implants and between two different positions for the same device in a cadaveric flatfoot model.

METHODS

The flatfoot model was created in ten cadaver feet through ligament sectioning and cyclic loading. Three kinds of arthroereisis procedures were evaluated: Talar-Fit (type I self-locking wedge implant) anchored in the sinus portion of the tarsal sinus (T-sinus group), Talar-Fit in the canalis portion (T-canalis group), and HyProCure (type II) in the canalis portion (H group). Corrective ability in the sagittal and transverse planes were measured with clinometers. Contact pressure was measured with pressure-sensitive films.

FINDINGS

T-canalis group provided more sagittal (mean difference for size 10 mm: 1.9°, P = 0.014; mean difference for size 11 mm: 3.1°, P = 0.037) and transverse (mean difference for size 8 mm: 1.8°, P = 0.049; mean difference for size 11 mm: 2.2°, P = 0.049) corrections than T-sinus group. The flattening process shifted the peak pressure of the posterior subtalar joint to the posteromedial side (P < 0.05) and arthroereisis helped the distribution of contact pressure restore uniformity (all P > 0.05).

INTERPRETATION

A self-locking wedge implant inserted in the canalis portion of the tarsal sinus achieved better correction than an implant inserted in the sinus portion.

Flexible Progressive Collapsing Foot Deformity: Is There Any Role for Arthroereisis in the Adult Patient?

Over the last two decades there is a growing interest in the adult literature for subtalar joint arthroereisis. Parallel to this interest, there have been improvements in the design and biomechanics of the implant, although the main indication of subtalar joint arthroereisis in adults is not clear. Most studies show significant improvement in postoperative clinical scores and visual analog scores. Sinus tarsi pain, being the most common complication, is the main determinant of clinical satisfaction. This review focuses on the role and complications of subtalar joint arthroereisis in the adult population.

Mid-term Results of Subtalar Arthroereisis with Talar-Fit Implant in Pediatric Flexible Flatfoot and Identifying the Effects of Adjunctive Procedures and Risk Factors for Sinus Tarsi Pain

Objectives

To (i) report the mid‐term outcomes of subtalar arthroereisis using Talar‐Fit implant for the treatment of flexible flatfoot patients; (ii) compare clinical and radiographic outcomes between arthroereisis with and without adjunctive operative procedures to investigate the effects of adjuncts on the outcomes; and (iii) analyze the risk factors associated with sinus tarsi pain, which is the most common postoperative complication of arthroereisis.

Methods

Thirty‐one flexible flatfoot children and adolescents (46 feet) treated with subtalar arthroereisis using Talar‐Fit implant from June 2014 to May 2019 were retrospectively analyzed. The feet were divided into four treatment groups: (i) arthroereisis alone, (ii) arthroereisis with gastrocnemius recession, (iii) arthroereisis with Kidner procedure, and (iv) arthroereisis with gastrocnemius recession and Kidner procedure. Clinical function was evaluated based on the American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score. The following angles were measured for radiographic evaluation: talar‐first metatarsal angle, calcaneal pitch angle, and talar declination angle on the lateral view; and talar‐first metatarsal angle, talocalcaneal angle, and anteroposterior talonavicular coverage angle on the anteroposterior (AP) view. The paired Student's t‐test was used to compare the pre‐ and postoperative angular measurements and AOFAS scores. The Wilcoxon rank‐sum test was undertaken to determine the outcome differences among four treatment groups. Multivariate logistic regression analysis was used to analyze risk factors for sinus tarsi pain. P value <0.05 is considered statistically significant.

Results

The mean follow‐up of the feet was 32.8 months (range, 10–71 months). The mean AOFAS score significantly improved from 55.5 ± 14.5 preoperatively to 86.3 ± 9.9 (P < 0.001). Comparison of radiographic outcomes showed that the lateral talar‐first metatarsal angle decreased by a mean of 19.1° ± 11.9° (P < 0.001), the calcaneal pitch angle increased by a mean of 5.4° ± 3.4° (P < 0.001), the talar declination angle decreased by a mean of 14.8° ± 9.9° (P < 0.001), the AP talar‐first metatarsal angle decreased by a mean of 15.6° ± 10.3° (P < 0.001), the AP talocalcaneal angle decreased by a mean of 7.2° ± 8.3° (P = 0.001), and the AP talonavicular coverage angle decreased by a mean of 20.4° ± 9.0° (P < 0.001). There were no statistically significant differences with regard to AOFAS score and all angle measurements on both the AP and lateral views among the four treatment groups. There was one dislocation case caused by a fall 6 weeks after surgery, which was treated nonoperatively. The incidence of sinus tarsi pain was 13% and logistic regression analysis indicated that patients with a longer distance from the tail end of the implant to the lateral calcaneal wall had 38.8% greater odds of developing sinus tarsi pain.

Conclusions

The mid‐term clinical and radiographic results were satisfactory in patients who underwent the subtalar arthroereisis procedure using Talar‐Fit implant, alone or in combination with other adjuncts, for the treatment of flexible flatfoot.

Finite element analysis of subtalar joint arthroereisis on adult-acquired flexible flatfoot deformity using customised sinus tarsi implant

Background

Subtalar arthroereisis may cause sinus tarsi pain complications. In this study, we aimed to introduce a customised implant that facilitated treatment effect and less impingement. The biomechanical outcome between the intact and implant conditions was compared using finite element analysis.

Methods

A female patient with flatfoot (age: 36 years, height: 156 ​cm, body mass: 51 ​kg) was recruited as the model patient. The customised implant was designed from the extracted geometry. Boundary and loading conditions were assumed from the data of a normal participant. Four gait instants, including the ground reaction force first peak (25% stance), valley (45%), initial push-off (60%) and second peak (75%) were analyzed.

Results

The navicular height was elevated by 4.2% at 25% stance, whereas the strain of the spring, plantar cuneonavicular and plantar cuboideonavicular ligaments were reduced. The talonavicular joint force decreased and the calcaneocuboid joint increased by half and 67%, respectively, representing a lateralised load pathway. There was a stress concentration at the sulcus tali reaching 15.29 ​MPa

Conclusion

Subtalar arthroereisis using a customised implant may produce some positive treatment effects in terms of navicular height elevation, ligament strain relief and lateralised joint loading pathway. Although the concentrated stress at the sulcus tali did not exceed the threshold of bone breakdown, we could not rule out the potential of vascular disturbance owing to the remarkable elevation of stress. Future study may enlarge the contact area of the bone–implant interface by considering customisation based on the dynamic change of the sinus tarsi during walking gait.

The translational potential of this article

Geometry mismatch of prefabricated implants could be the reason for complications. With the advancement of 3D printing, customising implant becomes possible and may improve treatment outcome. This study implemented a theoretical model approach to explore its potential under a simulation of walking.

Comparison of Extraosseous Talotarsal Stabilization Implants in a Stage II Adult-Acquired Flatfoot Model: A Finite Element Analysis

Subtalar arthroereisis has been proved to be an efficient method for correcting flexible adult flatfoot. However, the optimal sinus tarsi implant is still debated and yet to be determined. In the present study, we compared the biomechanical effects of type I and II sinus tarsi implants in stage II adult-acquired flatfoot deformity (AAFD). First, a finite element model of stage II AAFD was established in which virtual surgery of subtalar arthroereisis was simulated. The indexes of plantar stress distribution, peak von Mises of the medial and lateral columns, strain of the medial ligaments and plantar fascia, arch height, talo-first metatarsal angle, calcaneus pitch angle, talonavicular coverage angle, and hindfoot valgus angle were all compared and analyzed. The results of the present study have validated the stage II AAFD finite element model by comparing the simulation results with the same parameters measured from weightbearing radiographs in the midstance phase. All the indexes showed that both types of arthroereisis can lower the plantar pressure and the strain of the medial ligaments that support the medial longitudinal arch and can shift the load of the medial column to the lateral column. They can also help to correct the deformity and restore the arch. However, the type II sinus tarsi implant design exhibited a more obvious effect than that of type I.

Plantar pressure distribution in a hyperpronated foot before and after intervention with an extraosseous talotarsal stabilization device-a retrospective study

Plantar pressure measurements have long been used by clinicians to provide information regarding potential impairments and disorders of the foot and ankle. Elevations in peak plantar pressures or a poor distribution of these pressures can be an indication of pathomechanics in the foot. Lower extremity deficits such as sensory impairment, foot deformities, limited joint mobility, and reduced plantar tissue thickness have been associated with high plantar pressures. The total pressures, pressure distribution, and peak pressures provide useful information to evaluate the abnormal functioning of the talotarsal joint. Instability of the talotarsal joint can result in excessive forces exerted on the joints and surrounding tissues in the foot that can then lead to dysfunction of the proximal musculoskeletal kinetic chain. In the present study, we performed a retrograde analysis of the pre- and postoperative measurements of the peak plantar pressures, peak forces, and area of contact between the foot and the ground during each phase of the gait cycle for 6 patients (12 feet) who had undergone a bilateral extraosseous talotarsal stabilization procedure using a type II extraosseous talotarsal stabilization device. After the procedure, a significant reduction was seen in the peak pressures (42%) over the entire foot and a significant increase in the contact area (19.7%) between the foot and the floor. This could imply that the extraosseous talotarsal stabilization procedure was effective in stabilizing the talotarsal joint complex, thus eliminating abnormal hindfoot motion and restoring the normal biomechanics of the foot and ankle complex, as indicated by a reduction and realignment of the peak plantar pressures and forces.

Extraosseous talotarsal stabilization using HyProCure®: preliminary clinical outcomes of a prospective case series

The present multicenter, prospective study evaluated the subjective outcomes in patients after extraosseous talotarsal stabilization using the HyProCure(®) stent as a standalone procedure for the treatment of recurrent and/or partial talotarsal joint dislocation (RTTD) in a population of pediatric and adult patients. RTTD has been cited as a possible etiology for a number of foot ailments and might contribute to the development of pathologic features localized more proximally in the weightbearing musculoskeletal chain. Correction of RTTD might, therefore, lead to the reduction of pathologic features associated with this deformity. A total of 46 feet in 35 patients were included in the present investigation. Subjective evaluation used the Maryland Foot Score assessment, which was obtained preoperatively and 1, 2, and 3 weeks, 1, 2, 3, and 6 months, and 1 year postoperatively. The mean overall scores improved from a preoperative value of 69.53 ± 19.56 to a postoperative value of 89.17 ± 14.41 at the 1-year follow-up. Foot pain decreased by 36.97%, foot functional activities improved by 14.39%, and foot appearance improved by 29.49%. The greatest magnitude of improvement occurred 4 weeks postoperatively, with gradual improvement continuing through to the 1-year follow-up. Implants were removed from 2 patients (2 feet, 4.35%). No unresolved complications were observed. The positive subjective outcomes resulting from the extraosseous talotarsal stabilization procedure suggest that the intervention employing the device we have described alleviates pain and improves foot function and appearance in patients with RTTD.